SNOWMELT RUNOFF ANALYSIS IN THE MOUNTAINOUS BASIN OF IRAN WITH LACK OF SNOW OBSERVATIONS

摘要

This study tests whether the lack of conventional ground-based snow observation for Snow WaterEquivalent (SWE) can be overcome by using other Hydro-meteorological data. To this end, two differentmethods are described. The first one is introducing a methodology using a Distributed HydrologicalModel (DHM) to estimate SWE, when the available data are just precipitation and river discharge. For thesecond one, a distributed version of a Temperature-index snow model is developed and applied, when theground-based data is limited to precipitation and temperature. Two methods are applied in the upstreamof Karaj basin (850 km~2), which is the most important water resources of Tehran, the capital of Iran. Theestimated SWE is used for snow melt runoff forecast. It is found that forecast runoff correlates well withobserved natural discharge. This high correlations suggest that a reliable SWE estimation and snowmeltrunoff forecasting can be constructed using the methods in the absence of snow observation.